Heating device



p 1 H. MATTHES ET AL 2,902,927

HEATING DEVICE Filed Oct. 30, 1956 2 Sheets-Sheet 1,

Sept. 1; 1959 H. MATTHES ET AL HEATING DEVICE Filed Oct. 30, 1956 2 Sheets-Sheet 2 F'IG.2

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United States Patent F HEATING DEVICE Huibert Matthes and Hendrik J. R. Matthes, Amsterdam, Netherlands Application October 30, 1956, Serial No. 619,328

Claims priority, application Netherlands November 4, 1955 7 Claims. (Cl. 126-93) This invention relates to heating devices and more particularly to liquid fuel burners or heaters of the type provided with a combustion chamber, at one end of which is fed,and in which a central tube is provided for supplying air thereto. The tube in this type of burner construction extends downwardly into the combustion chamber to nearly the level of the fuel and is provided with perforations, while at the other end it is in free communication with the atmosphere.

It is a principal object of the present invention to improve this type of heating device by providing an arrangement of the members so that complete, efiicient vaporization of the fuel is assured at all operating firing rates, thus assuring complete combustion without carbonization and formation of cake or hard carbonaceous deposits.

A feature of the space heater according to the present invention is that the tube, which serves for the supply of all or nearly all the combustion air, has perforations in its circumferential wall portion and extends downwardly into the combustion chamber from the top where the combustion gases leave this chamber. The circumferential wall of the combustion chamber is radially spaced from the tube and surrounds the tube like a sheath over its entire length, while below the perforated end or lower wall of the central tube an evaporation chamber is provided into which the fuel is fed. The evaporation chamber occupies only part of the end wall of the central tube and communicates with the interior of the tube through the central perforations in this wall. The circumferential Wall of thevaporization chamber is provided with a plate extending radially therefrom at some distance below the end wall of the central tube and substantially parallel thereto. The circumferential wall of the evaporation chamber walls are provided with perforations between the plate and the end walls of the tube, while the chamber portion below the plate is in open connection with the sheath-like combustion chamber. With this arrangement, if the supply of fuel to the evaporation chamber is small, because of a decreased firing rate, there will initially occur evaporation of fuel only in this chamber and these vapours will mix with the air entering through the central perforations of the end wall of the central tube. The mixture of vapour and air-formed in the evaporation chamber enters through the perforations in the circumferential wall of the evaporation chamber in a space above the plate where it receives air through the perforations at the bottom of the central air tube and is burned. As a result thereof the plate is greatly heated, viz. to a temperature of 800 to 900 C., so that it will act as a radiation plate for the complete evaporation of the fuel located on the bottom of the combustion chamber as soon as the fuel supply is increased.

Other objects, features and advantages of the invention will be understood from the following description and claims in conjunction with the accompanying drawice ings which illustrate, by way of example, preferred embodiments of the heater, and in which Fig. l is a vertical section of a heater provided with the present invention.

Fig. 2 is a fragmentary sectional view on an enlarged scale of the lower portion of the heater shown in Fig. 1, and

Fig. 3 is a fragmentary sectional view of a heater according to the invention showing another embodiment of an evaporation chamber and radiation plate according to the invention.

In accordance with the drawings in the center of a sheath-like combustion chamber 11 is disposed a downwardly extending air tube 14, which is in free communication with the atmosphere at its top portion 14a. The bottom end wall 14b of the air tube 14 has perforations 16 and in the circumferential wall of the tube 14 per forations 15 are provided.

The combustion chamber 11 is provided at the top with a discharge channel or duct 13 for the combustion gases.

The bottom 46 of the combustion chamber has a cylindrical recessed portion 47 into which a cylindrical tube portion 48 is inserted comprising a fuel-receiving chamber forming the lower part of the evaporation chamber. At 49 this tube portion 43 is connected with the feeding duct for the fuel for receiving fuel from a supply source, not shown. In the embodiment shown in Figs. 1 and 2 the upper part of the evaporation chamber is formed by a saucer-like plate 50 and by a ring 51, lying below the plate 50, the bottom of which carries in its center a stud or crosspiece 52 into which a bolt 53 is passed by means of which said ring 51 is secured against the plate 50 and these two elements are held against the bottom 14b of the central tube.

When little fuel is supplied the level of the fuel in the chamber 12 is, for example, at a level A so that only a small quantity of fuel will evaporate. This vaporized fuel receives air through the central perforations 16' of the bottom of the air tube and flows up through the openings 54 in the upright border of the plate 50 into the space above the plate in order to be mixed and burned with the air entering through the perforations 16 in the bottom of the tube 14- which is disposed outside the evaporation chamber. The combustion that takes place here causes the saucer-like plate 50 to be heated so that it acts as a radiation plate for causing a complete evaporation of the fuel at increased firing rates, as for example when the fuel level is at the level B on the bottom 46 of the sheath-like tube 11 after the supply of fuel is increased. As a result of this greater fuel supply and the increased evaporation rate caused by heated plate 50 the fuel vapours will rise in the shethlike tube 11 where they will receive air from the perforations 15 and be burned, so that the wall of the combustion chamber will start to act as a radiation wall. The gases of combustion are discharged through duct 13.

For lighting the stove a pipe 55 is provided through which an easily ignited combustible liquid such as a spirit is poured onto the bottom of the combustion chamber. This liquid can be ignited in known manner, for example, manually, and the burning spirit will heat the plate 50 and consequently also the ring 51 so that the oil in the chamber 12 will begin to evaporate and the vapours will burn as they flow through the holes 54.

It will be understood that the invention is not restricted to the described and illustrated embodiment as several modifications may be made therein within the scope of the invention. It is thus possible to construct the plate 50 in such a manner that it is not a part of the circumferential wall of the evaporation chamber 12.

3 Thus, as shown in Fig. 3, wherein for convenience, the various elements are similarly numbered as the respective elements in the embodiment of Figs. 1 and 2, the combustion chamber 12 is formed by a single annular member 51. The upper wall portion of the combustion chamber is not part of theradiation plate 50 as in the embedi'menflof Figs: '1 and 2. The radiation plate 50 is disposed circumferentially around annular member SI and is supported on the bottom of the combustion chamber 11 as shown. It will be understood, however, that the heater or combustion apparatus shown in Fig. 3 functions and operates in the same manner as the embodirnent heretofore explained at length, according to the invention as shown in Figs. 1 and 2.

What we claim and desire to secure by Letters Patent 1s- 1. In a space heater, in combination, means defining a combustion chamber, an air supply tubular conduit extending inwardly into said combustion chamber and being centrally disposed therein, said conduit terminating in" spaced relationship from the bottom of the combustion chamber and having its inwardly disposed end covered with a perforated plate and being provided with perforations on the side walls thereof, the opposite end of said conduit being open and in free communication with the atmosphere, an annular member disposed below the inner end of the conduit and mounted in spaced relationship from the bottom of said means defining the combustion chamber, a dished-plate member having a peripheral portion spaced axially from the inner end of the conduit and having a collar portion overlying said annular member thereby to define a fuel evaporation chamber in combination with said annular member, the peripheral portion of said dished-plate member extending radially from said evaporation chamber, said dishedplate member having perforations communicating with the interior of said evaporation chamber, and means for delivering liquid fuel into the interior of said evaporation chamber.

2. In a space heater, in combination, means defining a combustion chamber having a cylindrical recessed portion on the bottom thereof, an air supply tubular conduit extending inwardly into said combustion chamber and centrally disposed therein, said conduit terminating in spaced relationship from the bottom of the combustion chamber and having its inwardly disposed end cov- 'ered with a perforated plate and provided with perforations on the side walls thereof, the opposite end of said conduit being open and in free communication with the atmosphere, an annular member disposed below the inner end of the conduit and extending into the bottom cylindrical, recessed portion of the combustion chamber and mounted to provide communication between the interior of said annular member and the interior of said recessed portion, a dished-plate member having a peripheral portion disposed in spaced relationship from the inner end of the conduit and an integral collar portion overlying said annular member thereby to define a fuel evaporation chamber in combination with said annular member, said dished-plate member having the peripheral portion extending radially outward from said evaporation chamber and said collar portion having perforations communicating with the interior of said evaporation chamber, and means for delivering liquid fuel into the interior or said evaporation chamber and said recessed portion.

3. In a space heater according to claim 2. in which said dished-plate member has a diameter greater than the diameter of said supply conduit.

4. In a space heater according to claim 2, in which said annular member has a diameter smaller than the diameter of said conduit and is disposed coaxial with said conduit.

' 5. In a space heater according to claim 2, in which said means for delivering fuel into the evaporation chamber and said recessed portion, comprises a fuel-receiving chamber extending downwardly from said recessed portion and having one end in free communication with said recessed portion.

6. In a space heater, in combination, means defining a combustion chamber, an air supply tubular conduit extending inwardly into said combustion chamber and centrally disposed therein, said conduit terminating in spaced relationship from the bottom of the combustion chamber and having its inwardly disposed end covered with aperforated plate and provided with perforations on the side walls thereof, the opposite end of said conduit being open and in free communication with the atmosphere, an annular member defining an evaporation chamber in combination with the inner end of said air supply conduit, said annular member being disposed below the inner end of the conduit and mountedin spaced relationship from the bottom inner surfaces of said means defining the combustion chamber, a dishedplate member having a peripheral portion disposed cireumferentially around said annular member in spaced relationship from the inner end of the conduit and said peripheral portion providing radiation surfaces extending circumferentially about the annular member, radially outward of said annular member, and substantially normal to the longitudinal axis of said air supply conduit, said annular member having perforations communicating with said evaporation chamber and located in a portion of said annular. member between the inner end of said conduit and a plane substantially corresponding with said radiation surfaces, and means for delivering liquid fuel into the interior of said evaporation chant.- her.

7. In a space heater, in combination, means defining a combustion chamber having a cylindrical recessed portion on the bottom thereof, an air supply tubular conduit extending inwardly into said combustion chamber and centrally disposed therein, said conduit terminating in spaced relationship from the bottom of the combustion chamber and having. its inwardly disposed end covered with a perforated plate and being provided with perforations on the side walls thereof, the opposite end of said conduit being open and in free communication with the atmosphere, means comprising an annular member disposed coaxially with said conduit defining an evaporation chamber in combination with the inner end of said air supply conduit, said annular member being disposed below the inner end of the conduit and extending into said bottom cylindrical recessed portion and mounted to pro vide communication between the interior of said annular member and the recessed portion, a dished-plate radiation member having a peripheral portion disposed axially spaced from the inner end of the conduit and providing radiation surfaces extending circumferentially about the annular member and radially outward of said annular member, said means defining the evaporation chamber having perforations communicating with said evaporation chamber and located in a plurality of positions disposed axially between the inner end of said conduit and a plane substantially corresponding with said radiation surfaces, and means for delivering liquid fuel into the interior of said evaporation chamber.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Switzerland Oct. 31, 1939 

